I will put my words in his mouth
God said:
وَأَضَعُ كَلاَمِي فِي فَمِهِ، فَيُخَاطِبُهُمْ بِكُلِّ مَا آمُرُهُ بِهِ
And I will put my words in his mouth; and he shall speak unto them all that I shall command him." Deut.18: 18.
Allaah says about Muhammad (PBUH):
وما ينطق عن الهوى إن هو إلا وحي يوحى
Nor does he say (aught) of (his own) Desire. It is no less than inspiration sent down to him ( al-Quraan 53 : 3-4)
One of the numerous examples of '...and I will put my words into his mouth...' is mentioned below from the Quraan; the verses begin with the word 'Say':
قل هو الله أحد الله الصمد لم يلد ولم يولد ولم يكن له كفوا أحد
"Say (O Muhammad): He Is Allaah the One and Only; Allaah, the Eternal, Absolute; He Begetteth Not, nor Is He Begotten: And There Is None like unto Him. (Quraan 112:1-4)